(a) Field
Embodiments of the present disclosure are directed to a stereoscopic image display device.
(b) Description of the Related Art
An existing technique for displaying a stereoscopic image, that of using binocular disparity to obtain a left eye image and a right eye image and displaying the eye images as one stereoscopic image in the brain has been disclosed.
An auto-stereoscopic display technique has been developed in recent years, and such a structure is roughly divided into two types, i.e., a lenticular type using a lenticular lens and an optical barrier type. The merits and drawbacks of the two types are as follows.
In the case of a lenticular type, a plurality of long, thin band-like convex transparent mirrors are arranged in a repeated pattern along an axial direction, and a display image is divided into left and right images by using optical refraction. Then, the left image and the right image are respectively presented to a left eye and a right eye of a viewer, and a stereoscopic image is recognized using disparity. As compared with an optical barrier type, a lenticular type, in which the display image is divided into the left and right images using light refraction, has little optical light loss and high luminance, but has a restrictive light refractive index. Accordingly, the resolution is degraded by refraction of a frame portion of a lens structure. Further, the lens surface is frequently not smooth due to protrusions and depressions generated thereon by errors in the manufacturing process of a lenticular lens, thereby generating scattered faint light. In this case, errors such as reflection, glitter, grayness, etc., in the image or image quality deterioration caused by the scattered faint light are generated, thereby degrading the display image quality of all 3D images.
In contrast, an optical barrier type controls light emitted at a predetermined angle using barrier objects arranged in series. In this case, a display image limited to the predetermined angle is divided into left and right images using optical refraction. Then, the left image and the right image are respectively projected to a left eye and a right eye of a viewer, and a stereoscopic image is recognized by binocular disparity. As compared to a lenticular type, an image is projected onto one eye, which provides an image with higher precision. However, a lenticular type suffers from poorer luminance over the entire display image and image resolution due to inherent structural characteristics.
Further, a general stereoscopic image display device displays only a stereoscopic image, and thus may not smoothly convert between displaying planar images and stereoscopic images. This is because, since the lenticular lens and the optical barrier are disposed in front of or in back of a general display device, all planar images pass through the lenticular lens or the optical barrier, which divide the planar image into a left image and a right image.